Motor Oil Feb 2020 Test: Which Brand Wins?
In our Feb 2020 test we compared 2 motor oil options head to head. Shell Rotella Gas Truck came out on top. See the measured results, the runner-up, the budget pick, and a link to the full test video.
Shell Rotella Gas Truck
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Mobil 1
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The quick take
The short version of why each pick lands where it does, built straight from the measured results.
“Mobile 1 is a good motor oil, but in my opinion, Shell Gas Truck is slightly better.”
The measured results
Every number below is read straight from the test. Products are listed in the order they finished.
All measurements (14 more)+
Evaporative Loss
- 1Shell Rotella Gas Truck
lost 5.14 g, from 430.19 g to 425.05 g, after 2 hours at 420 F, less loss than Mobil 1, won this test
- 2Mobil 1
lost 7.42 g, from 411.17 g to 403.75 g, after 2 hours at 420 F, more loss than Shell
Lubricity Cold
- 1Shell Rotella Gas Truck
smaller wear scar than Mobil 1, won the cool oil lubricity test
- 2Mobil 1
larger wear scar than Shell, lost the cool oil lubricity test
Lubricity Hot
- 1Shell Rotella Gas Truck
smaller wear scar than Mobil 1 at 225 F, won the hot oil lubricity test as well
- 2Mobil 1
larger wear scar than Shell at 225 F, lost the hot oil lubricity test as well
Cold Flow Race
- 1Shell Rotella Gas Truck
both the new and cooked samples crossed the finish line about an inch and a half ahead of Mobil 1, won the cold flow test
- 2Mobil 1
finished about an inch and a half behind Shell in both the new and cooked oil samples
Lab Wear Metals
- 1Shell Rotella Gas Truck
no aluminum, chromium, iron, copper, lead, or tin detected
- 2Mobil 1
trace levels of aluminum, iron, and lead detected
Lab Moly
- 1Shell Rotella Gas Truck144 parts per million
about twice as much as Mobil 1
- 2Mobil 1
about half as much as Shell's 144 parts per million
Lab Potassium
- 1Shell Rotella Gas Truck81 parts per million
- 2Mobil 188 parts per million
Lab Calcium
- 1Shell Rotella Gas Truck1,171 parts per million
higher than Mobil 1's 903
- 2Mobil 1903 parts per million
lower than Shell's 1,171
Lab Magnesium
- 1Shell Rotella Gas Truck445 parts per million
less than Mobil 1's 618
- 2Mobil 1618 parts per million
more than Shell's 445
Lab Phosphorus
- 1Shell Rotella Gas Truck603 parts per million
slightly less than Mobil 1's 626
- 2Mobil 1626 parts per million
slightly more than Shell's 603
Lab Zinc
- 1Shell Rotella Gas Truck743 parts per million
more than Mobil 1's 687
- 2Mobil 1687 parts per million
less than Shell's 743
Flash Point
- 1Shell Rotella Gas Truck440 F
higher than Mobil 1's 425 F
- 2Mobil 1425 F
lower than Shell's 440 F
Total Base Number
- 1Shell Rotella Gas Truck7.1
lower than Mobil 1's 8.1
- 2Mobil 18.1
higher than Shell's 7.1
Viscosity At 210 F
- 1Shell Rotella Gas Truck
slightly higher than Mobil 1
- 2Mobil 1not tested
How it was tested
- evaporative loss and thermal breakdown resistance after 2 hours at 420 F
- lubricity and film strength wear scar test on cool oil
- lubricity and film strength wear scar test on oil heated to 225 F
- cold flow race at negative 40 F comparing new and heat cooked samples of each oil
- independent oil lab analysis of wear metals, anti-wear additives, detergents, dispersants, viscosity, flash point and total base number
“Mobile 1 is a good motor oil, but in my opinion, Shell Gas Truck is slightly better.”
